| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.flink.connector.base.source.reader; |
| |
| import org.apache.flink.annotation.PublicEvolving; |
| |
| import javax.annotation.Nullable; |
| |
| import java.util.Set; |
| |
| /** An interface for the elements passed from the fetchers to the source reader. */ |
| @PublicEvolving |
| public interface RecordsWithSplitIds<E> { |
| |
| /** |
| * Moves to the next split. This method is also called initially to move to the first split. |
| * Returns null, if no splits are left. |
| */ |
| @Nullable |
| String nextSplit(); |
| |
| /** |
| * Gets the next record from the current split. Returns null if no more records are left in this |
| * split. |
| */ |
| @Nullable |
| E nextRecordFromSplit(); |
| |
| /** |
| * Get the finished splits. |
| * |
| * @return the finished splits after this RecordsWithSplitIds is returned. |
| */ |
| Set<String> finishedSplits(); |
| |
| /** |
| * This method is called when all records from this batch have been emitted. |
| * |
| * <p>Overriding this method gives implementations the opportunity to recycle/reuse this object, |
| * which is a performance optimization that is important for cases where the record objects are |
| * large or otherwise heavy to allocate. |
| */ |
| default void recycle() {} |
| } |